You’re indoors in the sense that you’re protected from the weather and the elements, and the cave could even have some kind of covering or entrance area that could be considered a door or doorway. People have built homes in caves.
Is caving an outside, inside activity?
It depends if the cave has a door.
Some people live in huts or other types of human dwellings that don’t have entry doors. They have doorways.
When I was visiting the Philippines I saw homes on stilts that did not actually have doors, but I would certainly consider the inside of such a structure to be indoors. Pre-colonial architecture may not use a front door.
I recognize this isn’t a great argument, but it’s arguable I think in principle.
If you don’t go in a door you’re not indoors.
Pedantically speaking, I have never been in a door. I’ve opened doors and passed beyond the portal they were blocking, but I have never phased into or been sealed inside of a door. :p
You are consistent! I admire this.
Username aside, man has a point
Do I have to walk through the door? Can there just be a door at one of the entrances?
What if I enter a cave through a door installed in a doorway, but there are other entrances that don’t have doors?
What if you enter the cave through an opening where the door isn’t but I know the cave system has a door at one of the entrances elsewhere?
If you go in the door you’re indoors but if you don’t you’re outdoor.
This could lead to a strange situation where you enter the cave through a doorless entrance and leave through an entrance with a door, making the outdoors indoors in the split second before you fade from existence.